# CVE-2026-12223: Yealink SIP-T46U command injection in Web FastCGI Service

Source: https://junglewise.ai/threats/cve-2026-12223-yealink-sip-t46u-command-injection-in-web-fastcgi-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-15. Updated: 2026-06-15  
License: CC BY 4.0 with a link back

CVE-2026-12223 · Severity: medium · CVSS 5.5 · Published 2026-06-15

A security vulnerability has been identified in Yealink SIP-T46U business desk phones. An attacker on the same local network could potentially execute unauthorized commands on the device by manipulating network diagnostic settings. This could lead to unauthorized access to the phone's functions or disruption of communication services.

Technologies: [Yealink SIP-T46U](https://junglewise.ai/threats/technologies/sip-t46u). Vendors: [Yealink](https://junglewise.ai/threats/vendors/yealink).

## Quick answers

**Is CVE-2026-12223 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-12223 being exploited in the wild.

**How severe is CVE-2026-12223?** Medium severity, with a CVSS score of 5.5, published 15 June 2026.

**Which products and versions are affected?** Yealink SIP-T46U 108.86.0.118.

**Is there a fix for CVE-2026-12223?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-12223 attacked?** It is attacked from the adjacent network, in an operating system.

**Am I affected by CVE-2026-12223?** Check whether you run Yealink SIP-T46U at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A command injection vulnerability exists in the Yealink SIP-T46U firmware version 108.86.0.118. The flaw is located within the mod_webd.TFTPUploadIperf function of the Web FastCGI Service, specifically in the /api/inner/tftpuploadiperf endpoint. By manipulating the 'ip' or 'port' arguments, an attacker with low privileges and local network access can inject and execute arbitrary system commands. The vulnerability stems from improper neutralization of special elements used in a command (CWE-77). As of the disclosure date, the vendor has not provided a patch or response.

## Affected products

- Yealink SIP-T46U 108.86.0.118

## Timeline

- 2026-06-15: disclosed: Vulnerability disclosed via VulDB and NVD
- 2026-06-15: advisory

## References

- [http://cdn2.v50to.cc/T46U/T46U_mod_webd_TFTPUploadIperf_system_exec.zip](http://cdn2.v50to.cc/T46U/T46U_mod_webd_TFTPUploadIperf_system_exec.zip)
- [https://vuldb.com/cve/CVE-2026-12223](https://vuldb.com/cve/CVE-2026-12223)
- [https://vuldb.com/submit/834603](https://vuldb.com/submit/834603)
- [https://vuldb.com/vuln/370866](https://vuldb.com/vuln/370866)
- [https://vuldb.com/vuln/370866/cti](https://vuldb.com/vuln/370866/cti)

## Related threats

- [Yealink SIP-T46U stack buffer overflow in Web FastCGI Service](https://junglewise.ai/threats/cve-2026-12222-yealink-sip-t46u-stack-buffer-overflow-in-web-fastcgi-service)
- [Yealink SIP-T46U stack-based buffer overflow in Firmware Chunk Upload Handler](https://junglewise.ai/threats/cve-2026-12221-yealink-sip-t46u-stack-based-buffer-overflow-in-firmware-chunk)
- [Yealink SIP-T46U stack overflow in Firmware Chunk Upload handler](https://junglewise.ai/threats/cve-2026-12220-yealink-sip-t46u-stack-overflow-in-firmware-chunk-upload-handler)
- [Yealink SIP-T46U command injection in Web FastCGI Service](https://junglewise.ai/threats/cve-2026-12219-yealink-sip-t46u-command-injection-in-web-fastcgi-service)
- [Yealink SIP-T46U stack-based buffer overflow in Web FastCGI Service](https://junglewise.ai/threats/cve-2026-12218-yealink-sip-t46u-stack-based-buffer-overflow-in-web-fastcgi)